12 to 18 months

Most babies take their first steps on their own at around 12 to 13 months. Nearly all healthy children walk on their own somewhere between about 8 and 18 months.

Most toddlers start scribbling with a crayon or stick at around 13 to 14 months. Holding the crayon in their fingers rather than their fist comes later, often around 18 months.

Most toddlers start feeding themselves with a spoon or other utensil at around 15 months. In a large study in four countries, about half did so by about 15 months, with similar ages everywhere.

Many babies first go up stairs by crawling, at around 11 months. Walking up stairs holding a hand or rail comes later: in four countries, about half did so by about 17½ months.

Most babies start simple pretend play, like feeding or rocking a doll or teddy, around their first birthday. In large studies of parents' reports, about half did this by about 11 to 14 months, and 9 in 10 by about 16 months.

Many toddlers help an adult who is struggling, like handing over something out of reach, from around 14 to 18 months, without being asked or rewarded.

In a large study in four countries, about half of children drank from a cup by about 13 months, but the age varied a lot between countries, from under 9 months to over 16.

In a large study in four countries, about half of children could take off a piece of clothing by about 15 months, but the age varied hugely between countries, from about 9 months to about 2 years.